EF-S Lens, why bother?

[soupdragon]

It occurs to me that an EF lens on a digital camera will appear edge to edge sharper than an EF-S lens.
I think this is the case due to the EF lens producing a larger image circle.
Given anything less than a 35mm sensor will effectively crop the outside of the image, and all lens perform better at the centre than the edge (particularly in terms of light fall off) most all EF lens will out perform EF-S lens edge to edge.
Unless I have this wrong and EF-S lens produce a sufficient image circle to cover a 35mm frame.

Any ideas anyone?

[cactusclay]

Sounds good to me.

[HKFEVER]

This is correct.

They are more concern in wide lens. Without EF-S, how can 1.6X has 16mm wide.

[Redbird_xo]

Without EF-S, how can 1.6X has 16mm wide.

Sigma 8mm F/4 EX will get you 12.8mm effective focal length. Got money, can defish? :D

[Andy_T]

With film cameras or with the 1Ds, the full frame image was and is sufficiently sharp corner to corner ... at least at the L line of lenses.

Of course it is nice that on a 1.6 body a lens that is not in the same range gives better performance, because you don't use it to its corners.

However, there are design considerations that give advantages for EF-S lenses, mainly in the wide angle range. An EF 10-22 that works on full frame would be a lot more expensive if it should deliver great quality. I haven't seen any decisive tests yet, but the quick review of the EF-S 10-22 versus the Sigma 12-24 hinted that the Canon lens might be a lot better.

It's really not a major issue. Most people don't have nearly as many wide lenses as tele lenses, but it helps to have at least one. So while we all enjoy the 1.6 crop in the tele area (your 200/2.8 is efficiently a 300/2.8, go compare prices) we can profit from either a very cheap but decent kit lens or a truly wide quality EF-S 10-22 lens.

I really don't understand why people keep ranting about EF-S lenses to the extent to put it into their sig. lines :(
If you don't like them, don't buy them. Period.

Best regards,
Andy

[mr.photoguy]

Are there any websites that compare the 10-22 to the 12-24?

[Andy_T]

Oops,

forgot to mention that the test was done by Luminous landscape.

Look here! (http://www.luminous-landscape.com/reviews/lenses/Canon-10-22mm-test.shtml)

As mentioned, it is not a real test, just a very quick review of the EF-S 10-22. The author promised a more elaborate test of the Sigma for a later point in time, but nothing is available so far.

Best regards,
Andy

[mr.photoguy]

Thanks Andy

[soupdragon]

Andy:

I am not really ranting on about EF-S lenses I just wanted to know if my rationale was correct.
The thread title was just to get someone to read it.
If an EF-S lens suited my needs I would get one I just like to know these things before I shell out cash.

Tony:

[HJMinard]

I think your rationale is correct. Why bother? Simply to get wide ... very wide ... without fisheye. To me, that's the only reason to consider an EF-S. (What were they thinking with the EF-S 60mm Macro? Doesn't make sense, in my opinion.) Sure, you can go wide with the full frame Sigma lens, but I really dislike the lack of front filter capability for a landscape lens.

[pcasciola]

Sigma 8mm F/4 EX will get you 12.8mm effective focal length. Got money, can defish? :DActually, the 8mm circular fisheye is one of the few lenses that completely breaks the 1.6x focal length multiplier rule. There is no horizontal cropping with the 8mm on a 1.6x sensor, only top to bottom.

[HKFEVER]

But you need to defish the picture.;)

[ScottE]

It is perfectly possible for engineers to design EF-S lenses that are a constant large aperture and sharp from corner to corner on an APS sized sensor, and yes, those lenses would not have to provide full coverage for a 35 mm film camera.

The fact that Canon has not seen fit to bring out L level EF-S lenses does not mean it cannot be done. It just means that Canon has not yet targeted the professional market for this level of camera.

The Olympus DSLR cameras use an even smaller sensor and Olympus is developing professional level lenses for those cameras. Whether the small sensor size will continue to limit the success of that line has yet to be seen.

In theory, EF-S lenses should be more compact and cheaper for the same quality of image you can get by using a lens designed for 35 mm film cameras. If Canon fully commits to this size sensor we will see that type of lens in the future. Right now they don't seem fully committed.

Scott

[raylks]

No matter it is EF or EF-S lens, as long as it performs, we would get it right?

[raylks]

Forget to express something:

I believe Canon is quite committed to establish its lower-end product line based on APS-C CMOS. The reason is that full frame sensor is still costly at the moment. Within these 3 years, I expect Canon releasing upgraded version of 20D and 350D based on the same size APS-C CMOS which will then further drilled down to the lower segment of the market.

Canon may produce a camera, based on EOS-3 (say EOS-3D), with a lower-cost full frame sensor once its production is mature. No matter how far is the high end products, the APS-C sensor still has its market potential though its end is lower.

[Jon]

An EF lens won't automatically, and/or always, appear sharper than an EF-S lens of the same focal length. You're correct that the EF-S has a smaller image circle, and that an EF lens on the smaller format sensor is using the better, center, part of the image circle, but it doesn't follow that an EF-S lens will produce a poorer quality image just because it has a smaller image circle. The problem in trying to analyze this is that there are only 3 EF-S lenses out there to date. Canon doesn't make a full-frame lens in the 10-22 mm range, so you can't make a useful comparison there (at best you'd be comparing the long end of that to the wide end of an L, whether the 16-35 or the 17-40, and the L would be stopped down from max under the same light). You could compare either the 17-85 or the 18-55 EF-S to the 17-40 L, but again you're comparing general-purpose lenses with L glass. The closest you're going to be able to do is across manufacturer's lines, between Canon's EF-S 10-22, say, and the Sigma 12-24 full-frame perhaps. And is that a fair comparison either?

[ScottE]

.....The closest you're going to be able to do is across manufacturer's lines, between Canon's EF-S 10-22, say, and the Sigma 12-24 full-frame perhaps. And is that a fair comparison either?

Not really. In order to design a full frame lens for a non-EF-S mount Sigma had to use a retrofocus design because the distance between the film plane and the rear lens element would not be possible without interfering with the camera's mirror. That is inheritantly going to compromise in performance.

It would be more interesting to compare say a 300mm f/2.8 IS L lens designed for EF-S and the current one designed for 35mm film. The lens could be much smaller and lighter and should cost less because the lens elements would be smaller. Also, since the lens elements are smaller diameter, the design and manufacture should be easier so there is a good chance that image quality would be better.

Come on Canon. How about an EF-S 500mm f/4 IS L lens that will be much more enjoyable to carry in a back pack and a little lighter on the wallet?

Scott

[MarkH]

Come on Canon. How about an EF-S 500mm f/4 IS L lens that will be much more enjoyable to carry in a back pack and a little lighter on the wallet?

Scott

Good idea, BUT: The L series are the professional lenses, the 1 series bodies are the professional bodies. The pro bodies are not compatible with EF-S.

I think Canon would be reluctant to make a 500mm L lens that the pro with a 1 series can't use. (By 1 series I mean the 1V as well as the 1D, 1Ds, 1DMkII, 1dsMkII)

[Tom W]

Good idea, BUT: The L series are the professional lenses, the 1 series bodies are the professional bodies. The pro bodies are not compatible with EF-S.

I think Canon would be reluctant to make a 500mm L lens that the pro with a 1 series can't use. (By 1 series I mean the 1V as well as the 1D, 1Ds, 1DMkII, 1dsMkII)

Not only that, but a 500 mm f/4 lens will be about the same size whether it incorporates the EF-S mount or the EF mount. Problem is that as the lens gets longer, the image circle is not the limiting characteristic, but rather the aperture. First, it will have to have an optical focal length of 500 mm, just as it does now. So unless Canon uses some exotic technology like Diffractive optics, it will be just as long as today's 500 mm lens. Also, the 500 mm focal length at f/4 requires a minimum of 500/4 or 125 mm (almost 5 inches) diameter front glass element. This is a requirement of light collection rather than image circle. And that's just for the glass - add a few mm for the housing, and for the hood and, well, you'll have a lens that is pretty much the same size as the 500 mm lens is now.

[Adam Hicks]

And before we make any judgements on the EF-S line, I'm REALLY interested in seeing how the 60mm 2.8 does. I have been tempted to order this lens, but don't care about the Macro component too much, and already have the 50mm 1.4, so it's a little hard to justify. I'm guessing it's going to be a tack sharp lens though.

Adam

[Tom W]

And before we make any judgements on the EF-S line, I'm REALLY interested in seeing how the 60mm 2.8 does. I have been tempted to order this lens, but don't care about the Macro component too much, and already have the 50mm 1.4, so it's a little hard to justify. I'm guessing it's going to be a tack sharp lens though.

Adam

That addition to the lineup was a bit of a surprise to me. I suspect that it will be a very good lens, just as its longer big brother, the 100/2.8 Macro is. Unfortunately, it won't work in my camera.

[DocFrankenstein]

However, there are design considerations that give advantages for EF-S lenses, mainly in the wide angle range. An EF 10-22 that works on full frame would be a lot more expensive if it should deliver great quality. I haven't seen any decisive tests yet, but the quick review of the EF-S 10-22 versus the Sigma 12-24 hinted that the Canon lens might be a lot better.
I don't understand the comparison.

EF-S 10-22 is equal to (almost) 17-40 EF L
At the same price, I'd prefer the L, thank you very much.

EF 10-22 would be equal to EF-S 6-14mm
Neither of those lenses are possible with the current technology... be it sigma, canon or noink.

[Todd Jacobsen]

It occurs to me that an EF lens on a digital camera will appear edge to edge sharper than an EF-S lens.
I think this is the case due to the EF lens producing a larger image circle.
Given anything less than a 35mm sensor will effectively crop the outside of the image, and all lens perform better at the centre than the edge (particularly in terms of light fall off) most all EF lens will out perform EF-S lens edge to edge.
Unless I have this wrong and EF-S lens produce a sufficient image circle to cover a 35mm frame.

Any ideas anyone?


10-22...Bought it, love it, plan on IT being the ONLY EF-S lens I buy.

In the future, if an EF 10-22L came along, I'd sell the EF-S in a heart beat. Don't like body limited lenses...

[Tom W]

10-22...Bought it, love it, plan on IT being the ONLY EF-S lens I buy.

In the future, if an EF 10-22L came along, I'd sell the EF-S in a heart beat. Don't like body limited lenses...

Of all the EF-S lenses, this is the one that I would buy if I had the camera for it. I had the 17-40 on my 10D, and I loved it. But 17 mm just isn't real wide on a 1.6X sensor. The 10-22 by all accounts I've heard is a very good lens.

[rdenney]

I am not really ranting on about EF-S lenses I just wanted to know if my rationale was correct.
The thread title was just to get someone to read it.
If an EF-S lens suited my needs I would get one I just like to know these things before I shell out cash.

I don't think it matters what happens outside the image circle. If designing to a smaller image circle allowed Canon engineers to correct other faults, you could well end up with a better lens, even though you are using the "sweet spot" of lenses designed for 24x36.

And you could take that logic too far. Instead of using a Canon 85mm lens, why don't I use a medium-format 80mm lens with an adaptor? I would be using only the sweetest part of the sweet spot by pulling a 15x23 image out of the middle of a lens that covers a 56x56 frame. The answer is that the medium-format lenses require compromises to provide the necessary coverage to light up a medium-format frame, and those compromises affect the center of the lens as much as the edges. Thus, my medium-format 80mm lens might only produce 40 lines/mm resolution, which is fine for medium format that doesn't get enlarged that much by comparison. But it would be terrible for a 15x23 image. The Canon 85 can provide 80 or 100 lines/mm resolution because they didn't have to figure out how to make the lens light up a 56x56 frame.

Each lens has to be measured on its own terms. I might get fine service from a Sigma 12-24 by only using the center of the image, but I might have gotten a better design compromise still by using the 10-22 that was optimized for that smaller image and that didn't even have to provide even a mediocre image across the larger frame. (I have a 10D, though, and so it wasn't a choice I could make. Plus, I bought the 12-24 before the 10-22 came out.)

My beef with the EF-S lenses is that they signal an increasing commitment from Canon to stick with the APS format, rather than migrating the 24x36 format down to the affordable prosumer DSLR class like we all want. I suspect that's why they are opposed in sigs, etc. That doesn't mean an EF-S lens can't be outstanding.

Rick "who wants a bigger sensor and who therefore won't buy lenses that won't fill a bigger sensor" Denney